A two-tier network based mobile node for outdoor environments is presented in this paper. It is designed to maintain the end-to-end communication links for mobile sensor networks. The mobile node has sensing, computation, communication and locomotion components assembled by off-the-shelf modules. This mobile node is able to incorporate IEEE 802.15.4 and IEEE 802.11b/g protocols so as to acquire high throughput signals as well as regular low bandwidth data. The assessment of link quality and a simple PID based control scheme are also illustrated in this paper.